Several options for hanging Christmas lights won't damage gutters. Using shingle clips avoids any hardware contact with them, and using plastic gutter clips minimizes the likelihood of scratching gutters. Remember not to rest a ladder, especially a metal one, against the gutters, and use a ladder stand-off device or stabilizer if you need to use an extension ladder. 

Christmas lights typically do not need to be grounded like electrical circuits in your home do. However, it's crucial to use outdoor outlets equipped with ground fault circuit interrupters (GFCIs) for added safety. GFCIs can help protect against electrical shocks and are recommended for outdoor electrical connections when using Christmas lights.

To hang Christmas lights outside without nails, consider using alternatives like adhesive hooks, gutter clips, or even hot glue. These options allow you to secure lights to various surfaces without causing damage to your roof or siding. Be sure to clean and prepare the surface before applying these alternatives for better adhesion.

To get in the festive mood, you might turn to hanging holiday lights yourself. In many circumstances, DIY Christmas light installation can be cost-effective, not to mention fun. However, it’s best to consider any limitations to this task and how that might affect your overall project, like tall roofs. Consider hiring a Christmas light installer to place lights or decorations in hard-to-reach areas like roof peaks to avoid the risk of injury.